Packaging apparatus



Aug. 9, 1966 w. A. BROWN ET AL 3,264,794

PACKAGING APPARATUS 7 Filed March 26, 1963 5 Sheets-Sheet l WILBER A.BROWN CHARLES H. FAWKNER INVENTORS. EUGENE W. GEIGEL CHESTER D- RHODESBY W tv MM TTORNEY.

Aug. 9, 1966 w. A. BROWN ETAL 3,264,794

PACKAGING APPARATUS Filed March 26. 1963 5 Sheets-Sheet 2 240 eed WILBERA. BROWN CHARLES H. FAWKNER INVENTORS. EUGENE W. GEIGEL CHESTER D.RHODES ATTORNEY.

Aug. 9, 1966 w. A. BROWN ET AL 3,264,794

PACKAGING APPARATUS Filed March 26, 1963 5 Sheets-Sheet 3 WILBER A.BROWN CHARLES H- FAWKNER INVENTORS EUGENE W. GEIGEL CHESTER D- RHODES BYATTORNEY- United States Patent 3,264,794 PACKAGING APPARATUS Wilber A.Brown, Springfield, Charles H. Fawkner, Am-

herst, Eugene W. Geigel, Springfield, and (Ihester D.

Rhodes, Wilbraham, Mass, assignors to Monsanto Company, a corporation ofDelaware Filed Mar. 26, 1963, Ser. No. 267,978 8 Claims. (CI. 53-29) Thepresent invention relates to the packaging of materials in plastic bags.More specifically, this invention relates to packaging apparatus whichuses a continuous tube of plastic material fed to the apparatus from aroll of the material in flattened condition.

Up to the present time, the general method for packaging pulverulent orother materials of volumetric capacities of more than one cubic foot hasbeen to fill essentially rectangular bag blanks which are supplied tothe filling or bagging machine from a magazine containing the bag blanksor other type of stacked arrangement. When the body of the :bag wascomprised of paper or other materials which had some rigidity, fewdifiiculties were encountered with the general operations associated inthe packaging steps, i.e., bag blank pick-up, opening, filling, etc.However, with the advent of the thermoplastic type bags serious problemswere encountered when the more flexible thermoplastic materials wereused as packaging materials. In particular, the extreme flexibility ofmany of the thermoplastic materials which have been fabricated into bagshas caused serious difiiculties, i.e., plug-ups, jamming, etc. duringpickup and transfer of the bag blank from the magazine or stack to thefilling station. These problems were further aggravated due to thediificulties of opening and supporting the rather flexible bag blanksbefore and during the filling operation. It has now been found thatthese problems are substantially resolved by new and novel packagingmeans and expedients which are simple in application but which presenthitherto unappreciated results.

Accordingly, it is the principal object of this invention to provideimproved apparatus means and methods for packaging materials inthermoplastic bags.

Another object of this invention is to provide apparatus means andmethods for packaging materials which utilizes a continuous tube ofplastic material in flattened condition.

Other objects of the present invention will in part be obvious and willin part appear hereinafter.

These and other objects are attained by transversely sealing acontinuous tube of thermoplastic material at predetermined intervalsalong its length, transversely severing the tubular material adjacenteach seal to form a bag blank sealed at one end, transferring the bagblank to a filling station where it isfilled with materials to bepackaged, after which its open end is closed. A special expedient may beused for separating the parallel edges at the open end of the bagsutficiently to permit the bag to be filled which comprises clamping thebag blank across its width /2 to 1 /2 inches adjacent its open end andcausing a projection to move parallel and in contact with the open endof the bag.

The following drawings are provided for the purpose of illustratingvarious embodiments of the present invention.

FIG. I is a side view, partly in section and with parts broken,illustrating mechanism for feeding and severing a continuous tube ofthermoplastic film.

FIG. II is a front view, partly in section and with parts broken, of thesame embodiment shown in FIG. I.

FIG. III is a front view, partly in section and with parts broken, ofthe same embodiment shown in FIG. II except that the thermoplastic tubehas been severed form- "ice ing a bag blank which is in a stage oflateral advancement.

FIG. IV is a fragmentary side view, magnified and with parts broken,illustrating a modified embodiment of the present invention wherein theapparatus is adapted to heat seal the tube of thermoplastic film atpredetermined intervals.

Referring in detail to the figures of the drawings, and morespecifically to FIGS. I and H, there is schematically shown apparatusfor packing materials in thermoplastic bags.- More specifically, acontinuous tube of thermoplastic film 10 is unwound from roll 12 andadvanced by means of pull rolls 14 and 16 over support rolls 1'8 and 20,between the said pull rolls 1 4 and 16 to and between clamping belts 22aand 22b. In the embodiment shown in FIGS. I and II, the tubular filmmaterial 10 is shown transversely sealed such that the layers of thetube are adhered or fused together, at predetermined intervals along itslength, i.e., 24a, 24b, 24c, etc., as it is unwound from roll 12. Inthis embodiment, the tubular film 10 was sealed during a prior separateoperation not shown in FIGS. I and II. As illustrated in FIG. IY, it issometimes desirable to transversely seal the tubular film after it isunwound from roll 12 in timed conjunction with the later severingoperation.

In the embodiment illustrated in FIGS. I and II, color bands 26a, 26b,260, etc. are marked at one end of each transverse seal 24a, 24b, 24cetc., respectively, at a position that will enable the color bands topass directly in front of the lens of electric eyes 28 and 30 as thetubular film 10 advances. These bands may be of any color which issufiiciently distinct from the tubular film to permit detection by theelectric eyes. In general, it is preferable that the length of the colormark in the direction of advance be at least A3 of an inch or moredepending, of course, on the sensitivity of the electric eyes. Thepurpose of the color bands and the electric eyes are to control themovement of the plastic film 10 as it advances towards clamp belts 22aand 22b. Clamp belts 22a and 22b are designed to move together on tracks32a and 32b activated by pistons 34a and 34b when a predetermined lengthof film is positioned therebetween and film travel has been halted,after which knife 36 moves laterally across the tubular film severingsame.

In the sequence of operations, pull rolls 14 and 16 are revolved tounwind and advance the tubular thermoplastic film 10. In the course offilm advancement, a color bar marked on film 10 passes in front ofelectric eye 28 which detects the mark. Upon detection, electric eye 28transmits a signal via electric means, not shown, to stop pull rolls 14and 16 which in turn halt the advance of film 10. Since there is a timeinterval or lag between the detection and transmission of the signalfrom the electric eye 28, the color mark on film 10 will advance adistance beyond electric eye 28 before the film 10 is halted. To ensurethat this distance remains the same each time the film is halted, asecond electric eye 30 is positioned such that one of the color markswill come to rest in front of its lens. In the event the color mark doesnot come to rest in front of the electric eye 30, a signal istransmitted calling for either a manual or automatic adjustment of thefilm position. To optimize control, it is recommended that a slighttension be maintained between pull rolls 14 and 16. During properoperation, the electric eye system will cause the pull rolls to halt theadvance of the tubular film 10 such that seal 24b is slightly aboveknife 36 after which clamping belts 22a and 220 move together clampingthe tubular film l0 therebetween. Knife 36 then moves laterally severingthe tubular film 10 to form a bag blank 40 sealed at its lower or bottomend by seal 24a. As may be seen in FIGS. II and III, clamp belts 22a and22b initiate advancement of the now severed tube or bag blank -40laterally by movement of the belts on rollers 42a, 42b;

42c and 42dwhich causes the edge or open top 44 of bag blank 40 whichprojects above b'elts 22a and 22b. to strike projection 46 at itsforward corner forcing bag top' 44 to openor separate its parallel edgesfirst atits corner and then across theentire top Width of the bag as thebag is force passed and in contact with projection 46 by belts Z ZZz'and22b. If done properly, projection 462Wi1l cause the bag top 44 to opensufliciently to permit a filling nozzle 48 to enter for filling same,after Which the opening or bag top 44 is closed by means of tape orother suitable means not shown. Although the expedient used to open thebag blank appears to be simple, the positioning or relationship betweenprojection and bag top 44 is critical. jects between /2 to 1 /2 inchesdepending on the flexibility Forexample, unless bag top 44 proof the bagabove clamp belts 22a and 22b, the top edge of the bag will nottend toopenproperly; To further illustrate, if the top edge projects too highabove the belts, the flexibility of the thermoplastic film ,will. caus.both edges of the bag to be pushed to one side or. the

other without opening the bag blank. On the other hand,

if the bag top-does not project sufliciently above belts 22aand 22b, thebag will not open enough'to permit the filling spout to enter. When thebag is opened properly by projection 46, filling spout 40 will descendbetween the parallel edges of the bag blank 40 forcing belt clamps 22aand 22bto part sufliciently to permit'filling of the bag blank.

In the practice of the present invention, the tubular.

thermoplastic film material may be transversely sealed at intervalsalong its lengh before itis unwound, i.e., by the supplier or separatesealing operation, or the thermoplastic film material may be sealed asit is advanced FIG. IV illustrates a magnified through the apparatus.fragmentary portion illustrating a heat sealing mechanism 50'positionedin line immediately above the cutting knife 36. In the sequence ofoperations, when pull rolls Hand 16 have halted the advance of film 10,heating element 52 of the heat sealing mechanism 50 moves horizontallytowards film 1t? pressing film 10 against back bar 54 of the heatsealing mechanism 50. r The heating element 52 then fuses the layers ofthe tubular film together. Positioning the heat sealing mechanisnrSGimmediately above knife 36 has the advantage ofminimizing controlproblems by reducing and possiblyeliminating the need for theelectriceye system which positions the seal. However, it is obvious that theheat sealing mechanism may be located anywhere along the line. ofadvance of the tubular film 10 prior to the knife 36.=

/2 to 1 /2 inches adjacent its open end and causing a projection to moveparallel and in contact with the open end of the bag.

As mentioned earlier, the thermoplastic tube may be sealed at any timeprior to the tube severing operation either during a separate operationor in timed conjunction with the severing operation. Any suitable methodfor adhering or fusing the layers of the tube together in a line or bandextending transversely and completely across the length of the tube maybe used. The width? of the adhered or fused line or band may varyconsid-% erably although widths of Ms to of an inch are recommended forgood bonding while at the same time utiliz ing-a minimum area of seal.The preferred methodsof sealing are those which cause'the layers of thetubular film to .fuse together. This is generally accomplished by anelectric heating element although other. means ofobtainingthe proper;fusion temperature may-also be used.

In thepractice of this invention, .thesheet is severed in conjunctionwith the filling operation. 1. Consequently, the problems 'cause drbystacking the bag blanks as described heretofore'are avoided. Inotherwords, the: bag blank istransferred or: conveyedftosthe filling stationimmediately after it is severed fromsthecontinuoustube.

This is, inzefr'ect, an in situ bag-forming and packaging i operation...Any suitable means. maybe used to ,sever the bag blank fromthecontinuous tube .such as the shuttle-type knife described in;FIGS.-'Iand II; a rotary knife, guillotine type and the like. If desiredgthetubing may be preperforatediadjacent and parallel theseals to permitamechanical separation insteadof cutting the tube directly. Itisimportant, however, that: the tube be cut or separatedparallel the lineof seal immediately adjacent the advanced or forward edge of the heatseal;

In this manner, a bag blank .will. be formed-having a sealed lower endand an open upperzend ready forfilling;

In the illustrated embodiment, the movement of the sheet was controlledby an, electric eye system. However, it is obvious that any system whichwill fairly accurately advance the tube predetermined distances Willisuffice;

A'special feature of the bag forming and packaging operation are the,meanswused to: separate the parallel.

edges at the open end of the bag blank to permit a filling spoutto'enter. As described above, this is ac? complished by clamping the bagacross its width. a predetermined distance. below the open end of thebag and moving a projection parallel and in contact with the open end. 1

The thermoplastic tubular film can be fabricated from such plasticmaterials as polyethylene, polystyrene, polyethyleneterephthalatmpolyvinyl chloride, polyvinyl ace- 1 tate, polyvinyl-idenechloride, polyisobutylene, polypro The pre-.- ferred thermoplasticfilm-materialis polyethylene, a solid,

pylene, polytetrafluoroethylene; and the like.

tough polymer ofethylene which can be manufactured inv film forminthicknesses less than zone mil.

moisture permeability,. and consequently, is anexcellent material forpackaging uses.

The bags: formed in the practice; of this'invention ordinarily will havesubstantial volumetric capacity, e.g.,' at least .1 cubic foot, and'are,designed-primarilyto carry about 50 to pounds of such commonpulverulent; materials such as cement, ilour, fertilizer, carbon blaokchemicals and .the like. The .walls of the bag ordinarily will have athickness of the order of 5 to 10 mils, al-

though obviously the .walls may be thinner or thicker astindicated bythe use towhich the bags are to be put. If desired, the walls of the bagcan befabricated from i a plurality ofplies of-thickthermoplastic film.

The above descriptions and particularly'the drawings,

are set forth for purposes of illustration only. Many variations andmodifications thereof will be obvious to those skilled in the art; andcan be made without departing from the spirit and scope .of theinvention herein 1 described.

What is claimed is:

1., A method of packaging materials in plastic bags which'comprises thestepsloftransversely sealing a continuous tube .of thermoplastic film atpredetermined in- I tervals alohg its length, transversely severing thetubular one end, clamping the: blankbagacross its width adjacent theopen end-of the bag iblank, causing a ,projection:to move parallel-toandin contact with the open I end of said bag blank, whereby a fillingspout may enter;

the bag, transferring said bag blankwtoya filling station,

It is light in weight, extremely low :in water absorption and Layersofpolyethylene can be heat=sealed or fused together to present a strongbond.-.

filmvadjacent each, seal to ,form a bag .blank sealed at filling saidbag blank with materials to be packaged and closing said open end of thebag blank.

2. The method according to claim 1 wherein the sealing is accomplishedby heat sufficient to fuse the layers of the tube of thermoplastic filmtogether.

3. The method according to claim 1 wherein the plastic film ispolyethylene.

4. A bag forming and packaging apparatus adapted to use a continuoustube of thermoplastic film which comprises, in combination, sealingmeans for transversely sealing the thermoplastic tube at predeterminedintervals along its length, driving means for advancing the tubular filmalong a predetermined path, cutting means for severing the tubular filmparallel and adjacent each seal forming a bag blank sealed at one end,opening means for separating the parallel edges at the open end of saidbag blank comprising clamping means for clamping the bag blank acrossits width adjacent its open end and a projection adopted to moveparallel to and in contact with the open end of the bag and conveyingmeans for transporting said bag blank to a filling station.

5. The apparatus according to claim 4 wherein sealing means compriseheating means capable of fusing the layers of the tube of thermoplasticfilm together.

6. A bag forming and packaging apparatus adapted to use a continuoustube of thermoplastic film comprising, in combination, driving means foradvancing the tubular film along a predetermined path, control meanslinked to said driving means for halting the advance of said tubularfilm at predetermined intervals of film travel, sealing means fortransversely sealing the thermoplastic tube while said film isstationary, cutting means for severing the tubular film parallel and infront of its forwardmost seal to form a bag blank sealed at one endwhile said film is stationary, conveying means adapted (1) to clamp saidbag blank across its width adjacent the open end of said bag blank and(2) to force the open end of said bag blank against a projection toseparate the parallel edges at the open end of said bag blank, a fillingspout adapted to enter between said separated edges to permit materialsto fill said bag blank and closing means for sealing the open end of thefilled bag blank.

7. A bag forming and packaging apparatus adapted to use a continuoustube of thermoplastic film which comprises, in combination, sealingmeans for transversely sealing the thermoplastic tube at predeterminedintervals along its length, driving means for advancing the tubular filmalong a predetermined path, cutting means for severing the tubular filmparallel and adjacent each seal forming a bag blank sealed at one end,projection means for separating the parallel edges at the open end ofsaid bag blank and conveying means for transporting said bag blank to afilling station.

8. A bag forming and packaging apparatus adapted to use a continuoustube of thermoplastic film which comprises, in combination, sealingmeans for transversely sealing the thermoplastic tube at predeterminedintervals along its length, driving means for advancing the tubular filmalong a predetermined path, cutting means for severing the tubular filmparallel and adjacent each seal forming a bag blank heat sealed at oneend, projection means for separating the parallel edges at the open endof said bag blank, conveying means for transporting said bag blank to afilling station, filling means for charging the materials to be packagedinto said bag blank, and closing means for sealing the open end of saidcharged bag blank.

References Cited by the Examiner UNITED STATES PATENTS 2,322,430 6/1943Fay 53-179 2,576,542 11/1951 Schoen 53-29 2,612,738 10/1952 Salfisberg53-29 2,643,496 6/1953 Cloud 53-183 2,649,671 8/1953 Bartelt 53-112 X2,649,674 8/1953 Bartelt 53-183 2,754,644- 7/ 1956 Vergobbi et al. 53-292,929,180 3/1960 Abrams et a1. 53-29 FRANK E. BAILEY, Primary Examiner.

BERNARD STICKNEY, Examiner.

A. E. FOURNIER, S. ABEND, Assistant Examiners.

1. A METHOD OF PACKAGING MATERIALS IN PLASTIC BAGS WHICH COMPRISES THESTEPS OF TRANSVERSELY SEALING A CONTINUOUS TUBE OF THERMOPLASTIC FILM ATPREDETERMINED INTERVALS ALONG ITS LENGTH, TRANSVERSELY SEVERING THETUBULAR FILM ADJACENT EACH SEAL TO FORM A BAG BLANK SEALED AT ONE END,CLAMPING THE BLANK BAG ACROSS ITS WIDTH ADJACENT THE OPEN END OF THE BAGBLANK, CAUSING A PROJECTION TO MOVE PARALLEL TO AND IN CONTACT WITH THEOPEN END OF SAID BAG BLANK, WHEREBY A FILLING SPOUT MAY ENTER THE BAG,TRANSFERRING SAID BAG BLANK TO A FILLING STATION, FILLING SAID BAG BLANKWITH MATERIALS TO BE PACKAGED AND CLOSING SAID OPEN END OF THE BAGBLANK.